Closure device for a fuel tank

ABSTRACT

The invention relates to a closure device for a fuel tank in a motor vehicle. The closure device has a filling-level transmitter and a blocking element which both together form a constructional unit. The blocking element is adjustable so that is it movable to a position in which the blocking element closes an opening in the tank.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a closure device having a blocking bodyfor a fuel tank such as a fuel tank in a motor vehicle.

[0003] 2. Description of the Related Art

[0004] Fuel tanks for motor vehicles have a filler neck via which thefuel tank may be filled. As the tank is being filled, the fuel flowinginto the tank displaces gas in the tank. To avoid uncontrolled flowingaway of the displaced gas, tanks have ventilation systems via which thegas is conducted away in a defined manner both during the filling of thetank and during operation. Fuel should be prevented from entering theventilation system to ensure reliable functioning of the ventilationsystem, particularly as the tank is being filled.

[0005] It is generally known to allow the filler pipe to open into thefuel tank below the upper boundary wall thereof and to arrange theventilation system above this opening. A gas-filled space therebyremains above the liquid level in the tank and has the effect that afilling device feeding fuel into the tank via the filler pipe isswitched off by the pressure building up in the filler pipe. Thisprevents the overfilling of the tank and therefore prevents theventilation system from being filled with fuel when the tank isoverfilled.

[0006] German reference DE 197 38 198 A1 discloses a device whichprevents overfilling of the fuel tank in which control valves arearranged both in the ventilation system and in the filler pipe. Certainprocess parameters such as, for example, pressure and throughflowquantity are detected via a plurality of sensors which are arranged atdifferent locations in the tank and the filler pipe. The signalsgenerated by these sensors are passed to a control component which thenacts upon the control valves in response to the corresponding controlsignals A problem with this known device is the complicated installationof this system because of the multiplicity of signal and control lines.In addition to the increased outlay required for laying the lines,additional sealing measures are also required with respect to the tank.

SUMMARY OF THE INVENTION

[0007] The object of the present invention is to provide a closuredevice for a fuel tank which allows a reliable switching off of thefilling device and has a simple and robust construction and is easy toinstall.

[0008] According to the present invention, the object is achieved by aclosure device for a fuel tank having an opening which is to be closed,the closure device comprising a constructional unit formed by afilling-level transmitter and a blocking element. The blocking elementis adjustable so that it is movable into an orientation in which theblocking element closes the opening of the fuel tank

[0009] The closure device includes a filling-level transmitter and ablocking element which form a constructional unit. The blocking elementis movable and closes the opening in one position. The constructionalunit makes it possible for the closure device according to the inventionto be constructed relatively compactly. The closure device requires fewcomponents and therefore takes up little space. The present inventionobviates the need for lines which are complicated to lay and have to besealed with respect to the tank.

[0010] Accordingly, both the filling-level transmitter and the blockingelement may be held by a common carrier and arranged at the openingwhich is to be selectively closed. The carrier on which thefilling-level transmitter and the blocking element are held may bedesigned with an appropriate configuration to adapt to the most variedopenings and therefore to be used universally. Furthermore, the closuredevice may be assembled as a constructional unit outside the tank andfunctionally tested before installation, thereby simplifying theinstallation of the constructional unit in the tank.

[0011] The filling level transmitter of the present invention mayinclude any of the known filling-level transmitters.

[0012] In a further embodiment, the blocking element is actuated via amechanical link. The closure device may be made to be particularlysimple and robust if lever-type transmitters or submerged transmittersare used as the filling-level transmitter. In this case, a float orlever arm is used as the actuating element for the blocking element. Themechanical link may include a gear mechanism, a cam mechanism or a levermechanism arranged between the actuating element and the blockingelement to facilitate the actuation of the blocking element. Theblocking element may be a flap, a cone or a slide which is arrangedpivotably or rotatably. The gear mechanism and the lever mechanism maybe configured so that they only move the blocking element into itsclosing position after a certain filling level is reached. If the gearmechanism is a toothed-gear mechanism, a toothed-gear segment may beused instead of a complete toothed gear so that they only move theblocking element into its closing position after a certain filling levelis reached.

[0013] In a further embodiment according to the present invention thelevel transmitter is a lever-type transmitter pivotally mounted in abearing in a lever-type transmitter housing. In this case, the pivotarea of the lever arm extends beyond the bearing in the lever-typetransmitter housing so that the blocking element may be fastened to thelever arm. The closure device thereby requires particularly fewcomponents and can therefore be of very small construction.

[0014] In another embodiment of the present invention, the blockingelement is actuated electrically by a signal produced by thefilling-level transmitter being used to actuate the blocking element.This embodiment also obviates the separate installation of control andsignal lines because of the direct arrangement of the blocking elementon the filling-level transmitter. In this embodiment, any filling-leveltransmitters which indicate the filling level in the form of an electricsignal may be used. The blocking element of this embodiment may be a2-way directional control valve.

[0015] Other objects and features of the present invention will becomeapparent from the following detailed description considered inconjunction with the accompanying drawings. It is to be understood,however, that the drawings are designed solely for purposes ofillustration and not as a definition of the limits of the invention, forwhich reference should be made to the appended claims. It should befurther understood that the drawings are not necessarily drawn to scaleand that, unless otherwise indicated, they are merely intended toconceptually illustrate the structures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the drawings, wherein like reference characters denote similarelements throughout the several views:

[0017]FIG. 1 is a perspective view of a closure device for a fuel tankaccording to an embodiment of the present invention; and

[0018]FIG. 2 is a sectional schematic view of a tank having the closuredevice according to the present invention with the blocking element inan open position;

[0019]FIG. 3 is a sectional schematic view of a tank having the closuredevice according to the present invention with the blocking element in aclosed position;

[0020]FIG. 4 is a schematic view of an embodiment of a mechanical linkbetween the fill level transmitter and the blocking element;

[0021]FIG. 5 is another schematic view of an embodiment of a mechanicallink between the fill level transmitter and the blocking element;

[0022]FIG. 6 is another schematic view of an embodiment of a mechanicallink between the fill level transmitter and the blocking element;

[0023]FIG. 7 is a schematic view of another embodiment of a blockingelement according to t he present invention ; and

[0024]FIG. 8 is a schematic view of yet another embodiment of a blockingelement according to the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0025]FIG. 1 shows a carrier 2 placed onto the end of a filler pipe 1 ofa fuel tank 11 (see FIGS. 2 and 3). The carrier 2 has a tubular section3 and a housing 4. A rotatable flap 5 is arranged in the tubular section3 for rotating about a spindle 13. When the rotatable flap 5 is orientedhorizontally the tubular section 3 is open and when the rotatable flap 5is oriented vertically the tubular section is closed by the rotatableflap 5. A filling-level transmitter 6 is arranged on the housing 4 andhas a float 7 arranged on a lever arm 8. The lever arm 8 is mountedrotatably in the housing 4. An electric signal is obtained as a measureof the filling level by a sliding contact 9 which slides over aresistance mesh 10. A mechanical link 12 (see FIG. 2) is arranged in thehousing 4 for connecting the lever arm 8 in its bearing to the rotatableflap 5.

[0026]FIG. 2 shows the fuel tank 11 with a low liquid level. Because ofthe low liquid level, the lever arm 8 points downward and the rotatableflap 5 is moved to a horizontal orientation via the gear mechanism inthe housing 4. FIG. 3 shows the position of the lever 8 when the fueltank 11 is filled up to the maximum height. When the fuel tank is filledup to its maximum height, the lever arm 8 is pivoted upward via thefloat 7. In this position of the lever arm 8, the rotatable flap 5,which is connected to the lever arm 8 via the gear mechanism, is movedinto a vertical orientation so that the rotatable flap 5 closes the pipe1.

[0027] FIGS. 4-6 show different embodiments of the mechanical link 12.In FIG. 4, the mechanical link comprises a gear mechanism including afirst gear 16 connected to the lever arm 8 and a second gear 15 inmeshed engagement with the first gear 16 and connected to the spindle ofthe rotatable flap 5. FIG. 5 shows an embodiment in which the mechanicallink comprises a cam mechanism in which a cam 17 is arranged on thelever arm 8. As the lever arm 8 rotates, the cam 17 alters the positionof the rotatable flap 5. FIG. 6 shows a lever mechanism including alever 18 connected to the lever arm 8 for moving the rotatable flap 5.

[0028] Instead of a rotatable flap, a slide 20 may be used as a blockingelement to close the opening to the fuel tank as shown FIG. 7. Insteadof a mechanical link 12, the blocking element may be actuated viaelectrical signals generated by the level transmitter. For example, FIG.8 shows a two-way directional control valve 22 which is actuatable viaan electric signal from a fill-level transmitter 6 a which is asubmerged transmitter. In this embodiment, the blocking element is acone which is part of the two-way directional control valve.

[0029] The invention is not limited by the embodiments described abovewhich are presented as examples only but can be modified in various wayswithin the scope of protection defined by the appended patent claims.

[0030] Thus, while there have shown and described and pointed outfundamental novel features of the invention as applied to a preferredembodiment thereof, it will be understood that various omissions andsubstitutions and changes in the form and details of the devicesillustrated, and in their operation, may be made by those skilled in theart without departing from the spirit of the invention. For example, itis expressly intended that all combinations of those elements and/ormethod steps which perform substantially the same function insubstantially the same way to achieve the same results are within thescope of the invention. Moreover, it should be recognized thatstructures and/or elements and/or method steps shown and/or described inconnection with any disclosed form or embodiment of the invention may beincorporated in any other disclosed or described or suggested form orembodiment as a general matter of design choice. It is the intention,therefore, to be limited only as indicated by the scope of the claimsappended hereto.

We claim:
 1. A closure device for a fuel tank having an opening which isto be closed, said closure device comprising: a constructional unitincluding a filling-level transmitter arrangeable for determining offilling level of the fuel tank and a blocking element, wherein saidblocking element is adjustable so that it is movable into a position inwhich the blocking element closes the opening of the fuel tank.
 2. Theclosure device of claim 1 , wherein said filling-level transmittercomprises one of a lever-type transmitter having a lever arm and asubmerged transmitter.
 3. The closure device of claim 1 , wherein saidblocking element comprises one of a flap, a cone and a slide.
 4. Theclosure device of claim 1 , further comprising a mechanical linkconnected between said filling-level transmitter and said blockingelement and comprising one of a toothed-gear mechanism, a cam mechanismand a lever mechanism, wherein said blocking element is mechanicallyactuatable in response to said filling-level transmitter via saidmechanical link.
 5. The closure device of claim 1 , further comprising aspindle, wherein said blocking element is fastened to said spindle forone of rotation or pivoting.
 6. The closure device of claim 5 , whereinsaid filling-level transmitter comprises a lever arm and said spindle isdirectly connected to said lever arm.
 7. The closure device of claim 6 ,further comprising a float connected to said lever arm and wherein saidfloat and said lever arm comprise components of a mechanism driving saidblocking element.
 8. The closure device of claim 1 , wherein saidfilling level transmitter generates an electrical signal in response toa fill level of the tank and said blocking element is actuated inresponse to said electrical signal.
 9. The closure device of claim 8 ,wherein the blocking element comprises a 2-way directional controlvalve.
 10. The closure device of claim 1 , wherein said constructionalunit comprises a carrier which holds the filling-level transmitter andsaid blocking element.
 11. In a fuel tank of a motor vehicle having afiller pipe, a closure device comprising a constructional unit formed bya filling-level transmitter and a blocking element, wherein saidblocking element is adjustable so that it is movable into a position inwhich the blocking element closes the opening of the fuel tank, whereinsaid closure device is arranged at an end of the filler pipe situated inone of the fuel tank and a ventilation system of the fuel tank.